package myintnodedouble;

public class MyIntNodeDouble {
    private int num;
    private MyIntNodeDouble next;
    private MyIntNodeDouble prev;

    public MyIntNodeDouble(int num) {
        this.num = num;
        this.next = null;
        this.prev = null;
    }

    public int getNum() { return this.num; }
    public void setNum(int n) { this.num = n; }

    public MyIntNodeDouble getNext() { return this.next; }
    public void setNext(MyIntNodeDouble next) { this.next = next; }

    public MyIntNodeDouble getPrevious() { return this.prev; }
    public void setPrev(MyIntNodeDouble previous) { this.prev = previous; }

    public void insertAfter(MyIntNodeDouble newNext) {
        MyIntNodeDouble oldNext = this.next;
        this.next = newNext;
        newNext.prev = this;
        newNext.next = oldNext;
    }

    public void insertBefore(MyIntNodeDouble newPrev) {
        MyIntNodeDouble oldPrev = this.prev;
        this.prev = newPrev;
        newPrev.prev = oldPrev;
        newPrev.next = this;
    }

    public void delete() {
    this.next.prev = this.prev;
    this.prev.next = this.next;
    }

    public MyIntNodeDouble getFirst() {
        MyIntNodeDouble current = this;
        while (current.prev != null) {
            current = current.prev;
        }
        return current;
    }

    public MyIntNodeDouble getLast() {
        MyIntNodeDouble current = this;
        while (current.next != null) {
            current = current.next;
        }
        return current;
    }

    public void addFirst(int n) {
        this.getFirst().prev = new MyIntNodeDouble(n);
    }

    public void addLast(int n) {
        this.getLast().next = new MyIntNodeDouble(n);
    }

    public int size() {
        MyIntNodeDouble current = this.getFirst();
    if (current == null){
            return 0;
    }
        int size = 1;
        while (current.next != null) {
            size++;
            current = current.next;
        }
        return size;
    }

    public int whereAmI() {
        MyIntNodeDouble current = this.getFirst();
        int pos = 0;
        while (current != this) {
            pos++;
            current = current.next;
        }
        return pos;
    }

    public void reverse() {
        MyIntNodeDouble first = this.getFirst();
        if (first == null) {
              return;
        }
        MyIntNodeDouble lprev = first;
        MyIntNodeDouble current = first.next;
        first.next = null;
        while (current != null) {
            MyIntNodeDouble lnext = current.next;
            current.next = lprev;
            lprev = current;
            current = lnext;
        }
        first = lprev;
    }

    @Override public String toString() {
        String returnString = "A list with " + this.size() + " integers:";
        MyIntNodeDouble current = this.getFirst();
        while (current != null) {
          returnString += " " + current.num;
          current = current.next;
        }
        return returnString;
    }

    public static void main(String[] args) {
        // Create Nodes
        MyIntNodeDouble n1 = new MyIntNodeDouble(1);
        MyIntNodeDouble n2 = new MyIntNodeDouble(2);
        MyIntNodeDouble n3 = new MyIntNodeDouble(3);
        MyIntNodeDouble n4 = new MyIntNodeDouble(4);
        MyIntNodeDouble n5 = new MyIntNodeDouble(5);
        MyIntNodeDouble n6 = new MyIntNodeDouble(6);
        // Link Nodes Together
        n1.setNext(n2); n2.setPrev(n1);
        n2.setNext(n3); n3.setPrev(n2);
        n3.setNext(n4); n4.setPrev(n3);
        n4.setNext(n5); n5.setPrev(n4);
        n5.setNext(n6); n6.setPrev(n5);
        // Test methods
        System.out.println(n1);
        System.out.println(n4.whereAmI());
        n4.delete();
        System.out.println(n1);
        n4.addLast(7);
        System.out.println(n1);
        n3.reverse();
        System.out.println(n3);
    }

}

/*
 *run:
 *A list with 5 integers: 1 2 3 4 5
 *3
 *A list with 4 integers: 1 2 3 5
 *A list with 5 integers: 1 2 3 5 6
 *A list with 0 integers:
 *BUILD SUCCESSFUL (total time: 0 seconds)
*/